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authorHauke Mehrtens <hauke@hauke-m.de>2010-04-01 17:27:59 +0000
committerHauke Mehrtens <hauke@hauke-m.de>2010-04-01 17:27:59 +0000
commitbbe4a57177ed26935f0cbf164f44a5e493d1523e (patch)
tree8bb954085d53256da80aeefbee37e9f32cb567e2 /target/linux/brcm-2.4/files
parentcf4781cfbdf414bb79a5dd4cd41bfbd225efb6a6 (diff)
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brcm-2.4: fix commit r18413 "128MB ram problem"
This was missing in commit r20072 SVN-Revision: 20651
Diffstat (limited to 'target/linux/brcm-2.4/files')
-rw-r--r--target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c25
1 files changed, 16 insertions, 9 deletions
diff --git a/target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c b/target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c
index f635b4a..c974574 100644
--- a/target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c
+++ b/target/linux/brcm-2.4/files/arch/mips/bcm947xx/prom.c
@@ -21,25 +21,32 @@ void __init
prom_init(int argc, const char **argv)
{
unsigned long mem;
+ unsigned long max;
mips_machgroup = MACH_GROUP_BRCM;
mips_machtype = MACH_BCM947XX;
- /* Figure out memory size by finding aliases */
+ /* Figure out memory size by finding aliases
+ *
+ * BCM47XX uses 128MB for addressing the ram, if the system contains
+ * less that that amount of ram it remaps the ram more often into the
+ * available space.
+ * Accessing memory after 128MB will cause an exception.
+ * max contains the biggest possible address supported by the platform.
+ * If the method wants to try something above we assume 128MB ram.
+ */
+ max = ((unsigned long)(prom_init) | ((128 << 20) - 1));
for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
+ if (((unsigned long)(prom_init) + mem) > max) {
+ mem = (128 << 20);
+ printk("assume 128MB RAM\n");
+ break;
+ }
if (*(unsigned long *)((unsigned long)(prom_init) + mem) ==
*(unsigned long *)(prom_init))
break;
}
- /* Ignoring the last page when ddr size is 128M. Cached
- * accesses to last page is causing the processor to prefetch
- * using address above 128M stepping out of the ddr address
- * space.
- */
- if (mem == 0x8000000)
- mem -= 0x1000;
-
add_memory_region(0, mem, BOOT_MEM_RAM);
}